Cells (IMAGE) Michigan Medicine - University of Michigan Caption Compared to control (left), immune cells (right) promoted tumor sphere formation, an indication of cancer stemness. Credit University of Michigan Comprehensive Cancer Center Usage Restrictions For use in stories related to this research License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.